This invention relates generally to the field of communications, and more specifically to a system and method for providing multiple quality of service classes.
The use of packet data networks to transfer voice signals has become increasingly popular in recent years. These applications are often referred to as Voice over Internet Protocol (VoIP) or Internet Telephony applications. In these applications, analog voice signals are typically digitized, and the resulting data is segmented into packets. The packets are transmitted across the packet network to a destination node, where the packets are reassembled and the data converted back into analog signals.
Typical networks, such as the Global System for Mobile communication General Packet Radio Services (GSM/GPRS) network, use packet data protocol (PDP) contexts to support applications executed on a terminal unit. Each terminal unit uses a PDP context to support the transfer of packet data messages in the network. A single PDP context may support one application or multiple applications executed by a terminal unit. In conventional networks, each PDP context is associated with a network address, such as an Internet Protocol (IP) address.
Typical networks also use quality of service classes to identify how well an application executed in the network performs from the subscriber""s perspective. For example, quality of service classes may be based on the speed, accuracy, and dependability of the network from the subscriber""s point of view. Functions like data transfer operations may operate successfully using lower quality of service classes. These applications are usually not time-sensitive, so delays in the network are acceptable. On the other hand, real-time applications like Internet Telephony applications need higher qualities of service to perform optimally. Packets carrying digitized voice data need to arrive within a specific amount of time at the destination node. Otherwise, excessive delays reduce the quality of the voice signal that is produced at the destination node.
Conventional networks assign a quality of service class to each PDP context, and all applications executed by a subscriber under one PDP context receive the same quality of service class. To receive multiple quality of service classes, a subscriber typically establishes multiple PDP contexts, and each PDP context receives a different quality of service.
A problem with this approach is that conventional systems cannot differentiate between the applications executed under a single PDP context. A subscriber may execute a large number of applications under one PDP context, and only a few of the applications may require a high quality of service class. Conventional systems treat all of the subscriber""s applications similarly, so each application receives the same quality of service class. As a result, all of the subscriber""s applications may receive a high quality of service class, even though only a few of the applications actually require the high class to work optimally. A similar problem exists if the PDP context handles only a low quality of service level. An application requiring a higher quality of service class will not work well.
Another problem with this approach is that conventional systems cannot efficiently handle the traffic for applications executed by multiple subscribers. One subscriber who receives a high quality of service class may execute a large number of applications under one PDP context, and all of the applications receive the high quality of service. Because this subscriber""s applications are all receiving the high quality of service, other subscribers may be unable to receive that quality of service. The system may use network resources to provide all of the first subscriber""s applications with the high quality of service class, even though few of the applications require it. Even if the other subscribers wish to execute real-time applications, they may be forced to use a lower quality of service because network resources are unavailable. The conventional systems are unable to efficiently handle the traffic for multiple subscribers.
A further problem with this approach is that conventional systems assign each PDP context a separate IP address. A subscriber may receive multiple quality of service classes, but the subscriber must first establish multiple PDP contexts. This forces the conventional networks to assign multiple IP addresses to a single subscriber. The number of IP addresses may be limited in conventional networks, which also limits the number of PDP contexts that may be established by the subscribers in the networks. Some subscribers may be unable to receive multiple quality of services classes if the network cannot assign IP addresses to the additional PDP contexts established by the subscribers.
In accordance with the present invention, a system and method for providing multiple quality of service classes are provided that substantially reduce or eliminate disadvantages and problems associated with previously developed systems and methods.
In one embodiment of the present invention, a system for providing multiple quality of service classes to a subscriber using a terminal unit includes a gateway operable to communicate with a network and a base station coupled to the gateway. The base station is operable to communicate with the terminal unit over a wireless interface. The base station is also operable to receive a first packet associated with a first application and a second packet associated with a second application from the gateway. The applications are executed by the terminal unit. The base station is further operable to identify a first quality of service class associated with the first packet and a second quality of service class associated with the second packet using quality of service information. The quality of service information is associated with the first and second applications, and at least a portion of the quality of service information is identified by a network address. In addition, the base station is operable to communicate the first packet to the terminal unit using the first quality of service class and to communicate the second packet to the terminal unit using the second quality of service class.
In another embodiment of the present invention, a method for providing multiple quality of service classes to a subscriber using a terminal unit includes receiving a first packet associated with a first application and a second packet associated with a second application, where the applications are executed by the terminal unit. The method also includes identifying a first quality of service class associated with the first packet and a second quality of service class associated with the second packet using quality of service information. The quality of service information is associated with the first and second applications, and at least a portion of the quality of service information is identified by a network address. The method further includes communicating the first packet over a wireless interface using the first quality of service class, and communicating the second packet over the wireless interface using the second quality of service class.
Embodiments of the present invention possess many technical advantages. In one embodiment, a communications system differentiates between the applications executed by a subscriber under a single packet data protocol (PDP) context. Applications that are executed by the same subscriber under one PDP context may receive different quality of service classes. For example, real-time applications may receive higher qualities of service, while data transfer applications executed under the same PDP context receive lower qualities of service. This allows each application executed by the subscriber to receive an appropriate quality of service.
Another technical advantage is the ability to handle traffic for applications executed by multiple subscribers more efficiently. Each application under a PDP context may have a corresponding quality of service class, which allows the system to limit the high quality of service to applications that actually need it. Rather than providing the high quality of service to all applications executed by a limited number of subscribers, the system may be able to provide the high quality of service class to a larger number of subscribers. By establishing a quality of service class for each application, traffic for multiple subscribers executing multiple applications may be handled more effectively.
In addition, a subscriber may receive multiple quality of service classes without forcing the communications system to assign multiple network addresses to the subscriber. A subscriber may establish a single PDP context and receive multiple quality of service classes. The subscriber is not required to establish multiple PDP contexts, so the system is not forced to assign multiple network addresses, such as Internet Protocol (IP) addresses, to each subscriber. The system remains free to assign the IP addresses to other elements in system 10. This also allows the system to provide multiple quality of service classes to any number of subscribers. The system may not be limited by the number of available IP addresses.
Other technical advantages are readily apparent to one of skill in the art from the attached Figures, description, and claims.